This invention relates to a retainer for maintaining a socket upon a tool shank of a high speed rotary tool.
While many different designs have been proposed and utilized in the art under consideration, the present invention is concerned with the type using an elastic band positioned upon the tool socket for maintaining a holding pin in a hole formed in the socket and tool shank. Such an arrangement is disclosed, for example, in U.S. Pat. No. 2,881,884, issued on Apr. 14, 1959 to Lester A. Amtsberg. While the elastic band used in the Amtsberg patent is flat in cross-section, bands of circular cross section are known, i.e., "O" ring configuration. Such bands are generally positioned in a circumferential groove formed on the tool socket which groove coincides with the ends of the pin hole.
The problem with such elastic band arrangements is that at high speed, when the tool is running free, i.e., not driving a work piece, centrifugal force acting upon an uncentered holding pin can cause the pin to force or cam the elastic ring aside so that the pin is suddenly ejected from the hole and become a dangerous projectile.
The socket retainer of the present invention avoids the aforesaid problem of the prior art elastic band arrangements by utilizing a unique elastic band which cannot be dislodged by the socket holding pin when the tool is running at high speed.
The main object of this invention is to provide a socket retainer utilizing a unique elastic ring which cannot be dislodged from position upon the tool socket by the socket holding pin at high speed tool operation.
Another object is to provide a socket retainer which is of simple structure and which can be applied to a socket using an "O" type elastic retaining ring without additional changes in socket structure being required.